The application of tubular labels to product containers to enhance the appearance and add information is known and popular. Tubular labels for use on containers are typically supplied in flat condition. The flat tube is opened by being passed over a spreader, with the opened tube somewhat elliptical in cross section. In the known technology, the product containers are restricted to those having a relatively narrow upper portion compared to a relatively wide lower portion, e.g. a bottle. The present invention recognizes that it is desirable to apply such tubular labels to cylindrical containers that have a substantially uniform cross sectional area throughout their axial length, e.g. cans and jars, as well as to bottles. Cylindrical containers present a greater challenge to the application of tubular labels, especially tubular labels that are formed from flattened tubular material because the upper portion of the container is of full diameter.
Tubular labels are generally formed from an extruded plastic sheet material in order to shrink the label after placing it around the container. The label is initially formed from a flat sheet of plastic, and the label is made tubular by welding the opposed edges together. The formed tube is then flattened and rolled onto a core for further handling. The flattened tube retains creases at its edges. At the time of applying the tubular label to a container, the tube is opened by being passed over a spreader, and slipped over the container. The opened tube has a non-round cross sectional shape due to the initial flat condition of the tube and the creases. When the opened tube is moved off the spreader, the tube tends to become somewhat elliptical. In the case of a bottle, the lack of tube roundness does not significantly impair placing the tube over the container since the small bottle top is an easier target. However, in the case of a cylindrical container, the container top is of full diameter and the application of a non-round tubular label is more difficult. In an industrial environment in which large numbers of labels are to be put onto containers each minute, the difficulty is exacerbated.